第5周作业-时钟动画程序

《Java语言程序设计》P418 不动的时钟

不动的时钟由三个类组成StillClock.java ,
Display.java 和 MessagePanel.java。

StillClock.java

import java.awt.*;
import javax.swing.*;
import java.util.*;

public class StillClock extends JPanel {
private int hour;
private int minute;
private int second;

public StillClock(){
setCurrentTime();
}
public StillClock(int hour,int minute,int second){
this.hour=hour;
this.minute=minute;
this.second=second;
}

public int getHour(){
return hour;
}
public int gethour(){
return hour;
}

public void setHour(int hour){
this.hour=hour;
repaint();
}

public int getMinute(){
return minute;
}

public void setMinute(int minute){
this.minute=minute;
repaint();
}

public int getSecond(){
return second;
}

public void setSecond(int second){
this.second=second;
repaint();
}

protected void paintComponent(Graphics g){
super.paintComponent(g);

int clockRadius=
(int)(Math.min(getWidth(), getHeight())*0.8*0.5);
int xCenter=getWidth()/2;
int yCenter=getHeight()/2;

g.setColor(Color.BLACK);
g.drawOval(xCenter-clockRadius,yCenter-clockRadius,
2*clockRadius,2*clockRadius);
g.drawString("12", xCenter-5, yCenter-clockRadius+12);
g.drawString("9", xCenter-clockRadius+3,yCenter+5 );
g.drawString("3", xCenter+clockRadius-10, yCenter+3);
g.drawString("6", xCenter-3, yCenter+clockRadius-3);

int SLength=(int)(clockRadius*0.8);
int xSecond=(int)(xCenter+SLength*
Math.sin(second*(2*Math.PI/60)));
int ySecond=(int)(yCenter-SLength*
Math.cos(second*(2*Math.PI/60)));
g.setColor(Color.red);
g.drawLine(xCenter, yCenter, xSecond, ySecond);

int mLength=(int)(clockRadius*0.65);
int xMinute=(int)(xCenter+mLength *
Math.sin(minute*(2*Math.PI/60)));
int yMinute=(int)(yCenter-mLength*
Math.cos(second*(2*Math.PI/60)));
g.drawLine(xCenter,yCenter,xMinute,yMinute);

int hLength=(int)(clockRadius*0.5);
int xHour=(int)(xCenter+hLength*
Math.sin((hour%12+minute/60.0)*(2*Math.PI/12)));
int yHour=(int)(yCenter-hLength*
Math.sin((hour%12+minute/60.0)*(2*Math.PI/12)));
g.setColor(Color.green);
g.drawLine(xCenter, yCenter, xHour, yHour);

}
public void setCurrentTime(){
Calendar calendar=new GregorianCalendar();

this.hour=calendar.get(Calendar.HOUR_OF_DAY);
this.minute=calendar.get(Calendar.MINUTE);
this.second=calendar.get(Calendar.SECOND);
}
public Dimension getPreferredSize(){
return new Dimension(200,200);
}
}

本类是为时钟参数

Display.java

import java.awt.*;
import javax.swing.*;

public class DisplayClock extends JFrame{
public DisplayClock(){
StillClock clock=new StillClock();
MessagePanel messagePanel=new MessagePanel(clock.getHour()+":" + clock.getMinute() +
":" + clock.getSecond()  );
messagePanel. setCentered(true);
messagePanel. setForeground(Color.blue);
messagePanel. setFont(new Font("Courier",Font.BOLD,16));

add(clock);
add(messagePanel,BorderLayout.SOUTH);
}
public static void main(String[]args){
DisplayClock frame=new DisplayClock();
frame.setTitle("DisplayClock");
frame.setSize(300,350);
frame.setLocationRelativeTo(null);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setVisible(true);
}

}

MessagePanel.java

import java.awt.*;
import javax.swing.*;
import java.util.*;

public class StillClock extends JPanel {
private int hour;
private int minute;
private int second;

public StillClock(){
setCurrentTime();
}
public StillClock(int hour,int minute,int second){
this.hour=hour;
this.minute=minute;
this.second=second;
}

public int getHour(){
return hour;
}
public int gethour(){
return hour;
}

public void setHour(int hour){
this.hour=hour;
repaint();
}

public int getMinute(){
return minute;
}

public void setMinute(int minute){
this.minute=minute;
repaint();
}

public int getSecond(){
return second;
}

public void setSecond(int second){
this.second=second;
repaint();
}

protected void paintComponent(Graphics g){
super.paintComponent(g);

int clockRadius=
(int)(Math.min(getWidth(), getHeight())*0.8*0.5);
int xCenter=getWidth()/2;
int yCenter=getHeight()/2;

g.setColor(Color.BLACK);
g.drawOval(xCenter-clockRadius,yCenter-clockRadius,
2*clockRadius,2*clockRadius);
g.drawString("12", xCenter-5, yCenter-clockRadius+12);
g.drawString("9", xCenter-clockRadius+3,yCenter+5 );
g.drawString("3", xCenter+clockRadius-10, yCenter+3);
g.drawString("6", xCenter-3, yCenter+clockRadius-3);

int SLength=(int)(clockRadius*0.8);
int xSecond=(int)(xCenter+SLength*
Math.sin(second*(2*Math.PI/60)));
int ySecond=(int)(yCenter-SLength*
Math.cos(second*(2*Math.PI/60)));
g.setColor(Color.red);
g.drawLine(xCenter, yCenter, xSecond, ySecond);

int mLength=(int)(clockRadius*0.65);
int xMinute=(int)(xCenter+mLength *
Math.sin(minute*(2*Math.PI/60)));
int yMinute=(int)(yCenter-mLength*
Math.cos(second*(2*Math.PI/60)));
g.drawLine(xCenter,yCenter,xMinute,yMinute);

int hLength=(int)(clockRadius*0.5);
int xHour=(int)(xCenter+hLength*
Math.sin((hour%12+minute/60.0)*(2*Math.PI/12)));
int yHour=(int)(yCenter-hLength*
Math.sin((hour%12+minute/60.0)*(2*Math.PI/12)));
g.setColor(Color.green);
g.drawLine(xCenter, yCenter, xHour, yHour);

}
public void setCurrentTime(){
Calendar calendar=new GregorianCalendar();

this.hour=calendar.get(Calendar.HOUR_OF_DAY);
this.minute=calendar.get(Calendar.MINUTE);
this.second=calendar.get(Calendar.SECOND);
}
public Dimension getPreferredSize(){
return new Dimension(200,200);
}
}

运行结果：

正如类名，只是会记录运行的那瞬间的时间，不会运动